Abe Applebaum is a 32 year-old has-been, a small-city Ontario burn-out who drinks too much and expects too little. That’s what life has taught him.

But twenty years ago, Abe was someBODY, a Willowbrook kid who gained local and national film as a sleuth, “The Kid Detective,” solving petty thefts, vandalism and the like. Then his 14-year-old “receptionist” Grace (Kaitlyn Chalmers-Rizzato) disappeared, and little Abe, local celebrity, was at a loss — helpless to help her or figure out her fate.

Abe, played with a depressed and utterly deflated exhaustion by Adam Brody (“Ready or Not,” “Promising Young Woman”), knocks back another drink and stares into the abyss of who he used to think he was and who the world sees him as now. “The world” includes his parents (Wendy Crewson and Jonathan Whittaker).

“We’re not bailing you out again.”

The ice cream shop owner who gifted him with “free cones for life” doesn’t hide his resentment any time Abe drops in for a freebie. The folks who still call on his “services” are missing cats, trying to figure out if their dad is gay or if the classmate who claimed he spent his summer in training camp with The Mets is lying.

And his Dad wants to know if he’s even bothered to raise his rate.

“Do you still charge a QUARTER?”

“The Kid Detective” is a soft-spoken, deceptively wry Canadian variation of the time-honored trope of private eye fiction — a gumshoe in need of redemption, sobriety and that one case that came give him back his long-MIA mojo.

A high school girl (Sophie Nélisse) has that case.

“Somebody murdered my boyfriend.”

And even though Abe’s ready to remind anybody who doubts him “I’ve closed over 200 cases,” even though we’ve seen evidence of his logical, studied powers of observation, deduction and drawing conclusions, we and he know he’s way out of his league.

Evan Morgan’s script takes its time getting on its feet, saunters through the middle acts and quietly sets up and delivers a finale that starts surprising and turns shocking and then more shocking.

Caroline (Nélisse) is the audience’s surrogate, the naive kid Abe impresses with his smart questions, his cunning (unlatching windows of houses he might want to “visit” again) and his seeming grasp of the “psychological integers” of every case.

He can’t call on the cops, his Goth receptionist (Sarah Sutherland, Kiefer’s daughter) is useless and for all his acumen about knowing WHAT to do, he’s a big clumsy actually DOING it.

Through it all, Brody wears the stubble of the “Out of f—s to give,” the battered sportscoat of private eyes since the beginning of time and the resignation of a man stuck being who he was as a boy, and starting to realize it. It’s a performance of sly wit, annoyance and alcoholic depression.

With its lesser-known cast, “The Kid Detective” was always going to get lost in the cinematic shuffle, with or without a pandemic closing most theaters. But Morgan and his new muse have concocted a whodunit that could give Hercule Poirot a run for his money in a contest for the year’s best mystery.

And let’s not forget this is Morgan’s debut feature. If Rian Johnson (“Knives Out”) sees this, he’s going to be looking over his shoulder.

MPAA Rating: R for language, drug use, some sexual references, brief nudity and violence

Cast: Adam Brody, Sophie Nélisse, Wendy Crewson and Jonathan Whittaker

Credits: Written and directed by Evan Morgan. A Sony/Stage 6 release.

Running time: 1:37